Thermostatic cut-out



Patented 'Aug. 23, 19 32 UNITED STATES PATENT OFFICE CALVIN a. WERNER, or nAY'roN, omo, ASSIGNOR 'ro DELCO rnonnc'rs coaronA'rrozu,

' A CORPORATION or DELAWARE THEBMOSTATIC cU'r-oU'r Application filed February 19, 1931.

This invention relates to improvements in automatic electric switches.

It is among the objects of the present invention to provide an automatic electric .5 switch, adapted to be operated to break an electric circuit in response to temperature changes.

A further object of the present invention is to provide an automatic switch adapted to 1 break an electric circuit when an excessive current is flowing through said circuit.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawingwherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a perspective view of the elec trio switch showing the mechanism in a circuit-closing position.

Fig. 2 is a view similar to Fig. 1, showing the mechanism in the circuit-breaking position. 25 Referring to the drawing, the numeral designates the housing for the switch, said housing being constructed of any suitable insulating material. Within the housing there are provided two stationary contact plates 21 and 22, one at each end of said housing. The plate 21 supports a contact 23, while the plate 22 supports a contact 24. On the outside of the housing 20 a plate 25 is electrically connected with the plate 21, a similar plate 26 being in electrical connection with the plate 22. Terminal screws 27 are provided on the plates 25 and 26 respectively.

A thermostatic element or strip 30 isprovided within the housing 20, said strip car-' Serial No. 516,866.

suitable manner, this U-sha-ped member comprising parallel side portions 34 and 35. A cotter pin 36 is supported between said side members 34 and 35.

The toggle which is adapted yieldably'to maintain the thermostatic element in either its normal or its flexed position comprises two members 40 and 41. The member 40 is substantially rigid and is hingcdly secured to the lug 42 in the housing in any suitable manner. In the present instance the end of the member 40 has a notch 43 which pivotally seats within a groove 44 provided in the lug 42 of the housing. Member 40 is hingedly attached to the cotter pin 36 in any suitable manner.

The member 41 of the toggle is bi-metallic i and flexible, the one end thereof being anchored to the housing 20 by pins 45. The ad jacent ends of the members 40 and 41, or more specifically their free ends, have supported therebetween a compression spring 46, the one end of the spring engaging a reduced end of the member 40, the other a reduced end of the member 41.

As shown in the Fig. 1, spring 46' is exerting pressure downwardly upon the free end of the member 40 so that the thermostatic element 30 is being urged toward the contacts 23 and 22, thereby urging the contacts 31 and 32 of the thermostatic element into intimate engagement with the cooperating stationary contacts 23 and 24. In this position the tem- I perature is normal, that is, the circuit flowing from the stationary contact 24 through the 85 thermostatic element to the stationary contact 23 is substantially normal. At normal temperatures the member 41 of the toggle will be flexed upwardly toward the portion 50 of th housing 20.

When an abnormal current flows from the stationary contact 24 through the therm0- static element 30 and into the stationary contact 23, 'suflicient heat will be generated to raise the temperature and cause the thermostatic element to flex toward the toggle. This increased temperature will also cause the bimetallic member 41 to flex away from the portion 50 of the housing toward the thermostatic element 30 and, when the movement Fr of the thermostatic element 30 toward the toggle and the flexing of the bi-metallic member 31 toward the thermostatic element 30 has moved or tilted the spring 46 so that its axis slopes substantially downwardly from left to right as regards Fig. 1, then said spring exerting a force upwardly upon the member 40, will quickly move said member 40 toward the top of the housing 20 as regards Fig. 1 and thereby lift the thermostatic element 30 so that its contacts 31 and 32 will be disengaged from the cooperatingcontacts 23 and 24 respectively, as shown in Fig. 2. A rise in temperature suflicient to cause flexing of the thermostatic element to open the circuit will not only obtain from an abnormal flow of current through the said element but it also may result from an overheating of the motor or any other device upon which .the switch is mounted. Such overheating may re sult from overloads or high ambienttemperature.

Decreasing temperatures will cause the thermostatic element 30 to warp toward the position as shown in Fig. 1, and, when its movement causes the arm 40 to tilt the spring 46 so that it is inclined downwardly from right to left as regardsFig. 1, said spring will again return the thermostatic element 30 into the contact-closing position. It will of course be understood that at decreasing temperatures member 41 will be flexed toward the position shown in the Fig. 1.

In the present invention applicant has provided an electrical switch which, in response to temperature changes, is quickly shifted from one position into another. Supporting one end of the spring 46 upon a bi-metallic member movable in response to changing temperaturesparticularly in a direction opposite the movement of the thermostatic element which moves the other spring-tilting member, will greatly facilitate the quick shifting of the contact bearing thermostatic element.

The switch is of simple construction and design, providing good contact engagement and substantially quick contact disengagement whereby arcing at the contacts, which causes pitting, is substantially eliminated;

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An automaticswitch comprising, in combination, a thermostatic element normally as suming one position but adapted to flex into another position in response to a change in temperature; a switching means operated by said element; two movable members one of which is connected to the thermostatic element; and elastic means supported between said movable members and adapted yieldably to maintain said element in either its normal or its flexed position.

2. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to a change in temperature; a switching means operated by said element; two movable members one of which is hingedly supported at its one end, the other being flexible and anchored at its one end; an elastic element supported between the free ends of said movable members; and means connecting one of said members with the thermostatic element whereby said element is yieldably maintained in its normal or its flexed position.

3. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to a change in temperature; a switching means operated by said element; two movable members, a rigid and a flexible one, the former being pivotally supported at its one end, the latter being rigidly anchored at itsone end; a compression spring supported between the free ends of said members; and means connecting the pivotally supported member with the thermostatic element.

4. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to an increase in temperature; a switching means operated by said element; two movable members one of which is substantially rigid and pivotally supported at its one end, the other a bi-metallic member flexible in response to temperature changes and anchored at its one end; a spring supported between the free ends of said members; and means connecting the one member to the thermostatic element.

5. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to an increase in temperature; a switching means operated by said element; two inovable members one of which is substantially rigid and pivotally supported at its one end, the other, a bi-metal member, is anchored at its one end and is adapted to flex in a direction opposite the flexing of the thermostatic element in response to temperature changes; a spring supported between the free ends of said members; and means connecting the pivotally supported member with the thermostatic element.

6. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to an increase in temperature; a switching means operated by said element; a toggle having two members one of which is substantially rigid and ivotally supported at its one en the other being anchored at its one end and being flexible in response to temperature changes, said toggle also having a spring supported between the free ends 0 said members; and a link connecting the thermostatic element with the pivotally supported member of the toggle whereby flexing of said element in response to temperature changes will move the said member to shift its end of the spring,the flexible member warping, in response to said temperature changes, in a direction opposite to the movement of the other member thereby more quickly tilting the spring to cause the toggle to throw the thermostatic switch operating element into its other position.

7. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another'position in response to an increase in temperature; a switching means operated by said element; a link carried by the thermostatic element; a pivoted lever attached to said link whereby flexing of the thermostatic element will move said lever; a bi-metallic member anchored at its one end and movable in response to temperature changes in a direction op osite the movement of the pivoted lever by t e thermostatic element; and a compression spring connected between the free ends of the lever and bimetallic member.

combination, a thermostatic element nor- .mally assuming one position but adapted to flex into another position in response to an increase in temperature; a switching means operated by said element; and means arranged to apply a force to said thermostatic element tending to urge it into either its normal or its flexed position depending on the existing temperature, said means having an elastic element the ends of which are moved simultaneously in opposite directions to provide quicker action of the thermostatic switch operating element.

9. An automatic switch comprising, in combination, a thermostatic element normally assuming one position but adapted to flex into another position in response to an, increase in temperature; a switching means operated by said element; and means arranged 'to apply a force to said thermostatic element tending yieldably to maintain it in either one of its positionsdepending upon existing temperatures, said means comprising two levers, one connected to the thermostatic element and movable'therewith, the other being self-movable in response to temperature changes, so arranged as to move in a direction opposite the thermostatic element and a spring connected between the two levers whereby the thermostatic element is quickly shifted from one to the other position as it moves to either side of an intermediate point during flexing.

10. An automatic switch, comprising in combination, a thermostatic contact carrying member, a movably mounted member pivotally attachedto said contact carrying member, a second thermostatic member anchored at one end, a resilient member supported between said pivotally mounted member and said second thermostatic member, said thermostatic members acting cooperatively in response to temperature change for operating the switch.

11. In an automatic switch, the combination comprising, a bimetallic contact carrying strip, a second bimetallic strip anchored at one of its ends, a resilient member movable with the other end of said second bimetallic strip, and means including said bimetallic strlps and resilient member for actuating the switch in response to temperature change.

12. In an automatic switch, the combination comprising, a bimetallic contact carrying strip having a pivotal mounting, a second bimetallic strip anchored at one of its ends, a resilient member pivotally attached to the other end of said second bimetallic strip and coupled with said pivotal mounting, means includin one of said bimetallic strips for shifting t e pivotal mounting of the contact carryng StilPS for causing said resilient member to actuate the switch with a snap action. I

In testimony whereof I hereto aflix my signature.

' CALVIN J. WERNER. 

